A cerium oxide abrasive containing a slurry in which cerium oxide particles obtained by subjecting a cerium oxide compound obtained by calcining a hydrate of a cerium compound at a temperature of 350° C. or higher but of 500° C. or lower to a pulverizing process and then calcining it at a temperature of 600° C. or higher are dispersed in a medium is disclosed, for example, in Claims in a below-mentioned patent literature 1. In Example 1 in the below-mentioned patent literature 1, it is described that if a material that has been calcined at 400° C. for 2 hours is pulverized by a ball mill and is then re-calcined at 800° C. for 2 hours, a material whose particle diameter is uniform with the primary particle diameter being 200 nm is obtained. [patent literature 1: refer to Japanese Patent Laid-Open Publication No. Hei 10-106990 (Claims, Example 1)]
A cerium oxide abrasive containing a slurry in which cerium oxide particles with the median of a primary particle diameter distribution being 30 nm to 250 nm and the median of a particle diameter distribution being 150 nm to 600 nm are dispersed in a medium is disclosed, for example, in Claims in a below-mentioned patent literature 2. In Example 1 in the below-mentioned patent literature 2, it is described that by calcining cerium carbonate at 800° C. for 2 hours, a cerium oxide with the median of the distribution of primary particle diameters being 190 nm and the specific surface area being 10 m2/g is obtained. Furthermore, in Example 2 in the below-mentioned patent literature 2, it is described that by calcining cerium carbonate at 700° C. for 2 hours, a cerium oxide with the median of the distribution of primary particle diameters being 50 nm and the specific surface area being 40 m2/g is obtained. [patent literature 2: refer to Japanese Patent Laid-Open Publication No. Hei 10-152673 (Claims, Example 1 and Example 2)]
A production method for cerium dioxide (CeO2) in which cerium carbonate is turned into cerium monooxycarbonate by performing a heating process under a high humidity having a relative humidity of 80% or higher in a temperature range of 60° C. to 100° C., and then calcining is carried out, is disclosed, for example, in Claims in a below-mentioned patent literature 3. In Example 1 in the below-mentioned patent literature 3, it is described that hexagonal platy cerium carbonate is put into a constant temperature and humidity chamber, and a humidifying-drying process is performed at 85° C. and a relative humidity of 95% for 8 hours so as to obtain acicular cerium monooxycarbonate Ce2(CO3)2.H2O, and this is calcined at 400° C. for 2 hours so as to obtain a cerium oxide with the specific surface area being 153 m2/g, and this is re-calcined at 800° C. for 5 hours, so that a cerium oxide of 15.2 m2/g is obtained. Furthermore, in Comparative Example 2 in the below-mentioned patent literature 3, it is described that if hexagonal platy cerium carbonate is put into an autoclave and a hydrothermal process is performed at 120° C. for 8 hours, basic cerium carbonates Ce2(CO3)2.H2O in a hexagonal platy form and a spherical form are obtained, and the amount of production of cerium monooxycarbonate is 5% of the total, and the material is calcined at 400° C. for 2 hours so as to obtain a cerium oxide of 112 m2/g in specific surface area, and this is re-calcined at 800° C. for 5 hours, so that a cerium oxide of 2.8 m2/g is obtained. [patent literature 3: refer to Japanese Patent Laid-Open Publication No. Hei 7-81932 (Claims, Example 1 and Comparative Example 2)]